I am catching hell locating a rear bumper cover, tail light lenses and shrouds, and a liscense plate assembly for a 1985 monte carlo ss. If anybody out there knows of a supplier or source for these parts, please let me know.

Have you tried rockauto.com , or montecarloss.com , or dixiemontecarlodepot.com ? They might have what you need if you haven't tried them already. You can even call your local salvage yard(s) and if they don't have the parts, they can use a locator to try and get them for you.